Mars Pathfinder Science Results

Pathfinder investigated the dust in the atmosphere of Mars by observing
its deposition on a series of magnetic targets on the spacecraft. The dust,
it turned out, is highly magnetic. It may consist of small silicate (perhaps
clay) particles, with some stain or cement of a highly magnetic mineral
known as maghemite. This, too, is consistent with a watery past. The iron
may have dissolved out of crustal materials in water, and the maghemite
may be a freeze-dried precipitate.

This composite image shows particles adhering to magnetic target arrays
on the Pathfinder lander. Each array consists of five magnets that increase
in magnetic filed strength as seen from left to right. The red material
forming a bulls-eye pattern on the arrays is magnetic Martian dust deposited
from the atmosphere. An increase in magnetic dust deposition from Sol 10
to Sol 66 is clearly evident. By analyzing the patterns of dust on the
various magnets, scientists are able to measure the dusts' magnetic strength
and infer its composition.

The upper two images show the lower magnetic properties targets
on sols 6 and 13. The lower image shows the upper magnetic target on sol
26. It is clear that the patterns of dust have developed with time. For
more information on the background on this experiment, please visit the
team's homepage at http://ntserv.fys.ku.dk/mars.htm.

Magnetic properties experiment - Magnet arrays (440 nm)

The Mars Pathfinder Magnetic Properties
Experiment primarily involves an array of permanent magnets on the lander.
The magnets are assembled to produce a bulls-eye pattern of attracted dust
using an outer annular ring magnet, 18mm in diameter, surrounding a central
cylindrical magnet. In each of two magnet arrays, five such magnets of progressively
increasing strength, are mounted in magnesium blocks.

These magnets are intended to attract
any magnetic particles in the windborne dust. The picture shows a magnet
array on Sol 6 and on Sol 13. Dust has clearly accumulated on the two strongest
magnets. As more dust is attracted with time, we expect the patterns on
the magnets to become clearer.